Field View is a shepherd's hut in Little Polgooth, near St Austell. It's in a field so it's detached and private.
It's a proper off-grid glamping setup for two people. One room with a double bed, a small kitchen area, and a shower room. The bed has storage underneath it. There's a paved bit outside with a table and chairs.
You get bedding and towels. There's a TV, but it runs off solar power. The lighting is solar too, so you might need to be a bit mindful with it on cloudy days. There's parking right there.
You can bring up to two dogs. There's space to store bikes.
The pub is about a five minute walk. Pentewan Beach is a nice walk, about three miles through the lanes. You can get bikes delivered here if you want to ride the trail.
St Austell is ten minutes in the car for supermarkets and things. Mevagissey and Charlestown are close too, they're proper old fishing villages. The Lost Gardens of Heligan are very close, and The Eden Project is about a fifteen minute drive.
Useful links: National Trust Cornwall and Cornwall National Landscape.